Nepalese rescuers are using explosives to blast into hillsides in an increasingly desperate search for over 600 hydropower workers trapped in mud-filled tunnels along the Trishuli River. The operation intensified on Monday as fears grow for the workers, many of whom are feared to be among the nearly 4,000 people missing following devastating floods.

The incident highlights the vulnerability of Nepal's extensive hydropower infrastructure, which relies heavily on its mountainous river systems. Years of development have resulted in at least 11 projects being damaged or destroyed by the recent deluge, impacting the nation's primary energy source.

Families of the missing workers are clinging to hope, with some expressing frustration over the pace of the rescue. "The longer it takes, the more our hope dies," said Jiban Khadka, whose relative is trapped. "This operation must move much faster because every second is meaningful to us."

International teams, including military personnel from China and Nepal, along with experts from India, Korea, and Australia, are supporting the complex rescue efforts. Prime Minister Balendra Shah stated that 279 people had been rescued from the hydropower sites as of Monday, with a total of 11,379 people rescued overall.

An estimated 939 people have died in the flood disaster, which struck the Nepal-Tibet border region. The disaster management authority revised its missing person count to 3,925, including 592 foreign nationals. Roughly one in seven of those missing are believed to be employed at the damaged hydropower plants.

Some families hold onto hope due to the presence of oxygen systems within the tunnels. Sita Pandey, whose husband was working at a plant when the floods hit, noted, "I still have a 50% hope that he is alive because there is an oxygen system inside."

Rescuers have been pumping air into tunnels and attempted to access one plant's tunnel on Monday, but withdrew after finding no one inside. The challenging terrain and the nature of the disaster have made locating the subterranean structures difficult. "The actual signature of them has gone - everything is just missing. It looks like a lunar landscape," commented Australian engineer Arnold Dix, who is advising remotely.

The immediate focus remains on locating and accessing the trapped workers, while authorities grapple with the broader implications of the disaster for infrastructure, energy security, and the immense human toll. Unresolved questions linger about the timeline for future rescue attempts and the extent of the damage to other critical infrastructure across the region.